Facilities in Kalinin

Number one reactor at Kalinin NPP shuts down for second time in two weeks, raising concerns

MOSCOW – The Kalinin Nuclear Power Plant has again run into trouble for the second time in two weeks after its struggling No.1 reactor was plugged back into the power grid after a stoppage occasioned by a transformer fire on July 23, only to be shut down again yesterday. Andrei Ozharovsky, 05/08-2010 - Translated by Charles Digges

The nuclear plant, located between Moscow and St. Petersburg, has produced record lows of power output throughout July, falling short by half a million kilowatt hours of energy pumped into Russia’s energy grid.

According to the Kalinin NPP press office, “on August 5, 2010, at 3:07, the no. 1 reactor was taken off the grid by the actions of an automatic generator switch. The reasons for the event are currently being investigated.”

The No. 1 reactor therefore worked for only 11 days after it was plugged back into the grid on July 25. The reason for the shut down on July 23 was a fire at a piece of equipment called an outdoor switchgear, or an ORU-750kV in its Russian terminology. Whether the reason for the current shutdown is another fire is still unknown. It could be that workers were not successful in completing reliable repairs on the reactor and that the problems will persist, Bellona experts say.

Earlier, Russia’s state nuclear utility Rosenergoatom said that “the outbreak of the fire and the reasons for it were likewise eliminated on July 23.” But it is apparent that not all the failures of the electrical equipment at the NPP were discovered and eradicated.

The Kola Nuclear Power Plant in Russia’s northwest Murmansk Region ran into similar problems when its reactor unit No. 3, after a short stoppage, was not able to work for more than nine hours, and was shut down by automatic switches. Such events occur because Russia’s NPPs do not run at full power and are significantly cutting down their power contribution to the grid.

The Kalinin NPP press reported that the plant had produced “1,591 billion kilowatts per hour of electrical energy in July. One thousand four hundred and ninety four billion kilowatt hours were delivered into the energy grid. The installed capacity utilisation factor (ICUF) in July consisted of 71.29 percent.”

As such, some 6421 million kilowatt hours were not delivered into the national grid. Had the plant worked at full capacity on all three of its reactors, it would have delivered 2.332 billion kilowatt hours.

Tha Kalinin NPP’s installed capacity utilisation factor also strongly differs from the 90 percent promised by Rosatom, Russia’s state nuclear corporation, which oversees Rosenergoatom. Worn out equipment, human error and for under-preparation of NPPs to work in fire conditions contribute to this low installed capacity utilisation factor. "

Fire at the Kalinin Nuclear Power Plant shuts down No 1 reactor for two days

The transformer fire atop the Kalinin NPP on June 23, 2010.
Svetlana Zakharova

MOSCOW - As the result of a fire at an outdoor switchgear at the Kalinin Nuclear Power Plant north of Moscow on July 23, the plant’s Reactor Block 1 was shut down. Two days later, the No. 1 unit was re-plugged into the grid. Andrei Ozharovsky, 25/07-2010 - Translated by Charles Digges

On July 23, 2010 at 3:22 pm, reactor unit No 1 of the Kalinin NPP was shut down in connection with a fire that broke out at a 750 kilovolt outdoor switch gear (ORU in its Russian abbreviation). At 3:45 pm, the fire was extinguished by the actions of manned fire division 8 and 14,” read a statement from the press office of Rosnergoatom, Russia’s state nuclear utility.

It was later made public that the cause of the fire was leaking oil from damaged and oil-filled electrical equipment. The ORU 330 and ORU 750 continue to function at full gear.

Kalinin NPP is located in the town of Udomlya, in Tver Region in Central European Russia, to the north of Moscow. It operates three 1,000-megawatt reactors of the VVER-1000 type, and a fourth reactor is under construction and scheduled to be launched in 2011.
Another fire at a transformer

In less technical terms, a transformer at the Kalinin NPP burned. There are simply no other oil-filled eletrical devices in an outdoor switchgear system. But fires at NPPs are especially complicated even when they concern the electrical and not the nuclear equipment. If the fire spread to other equipment in the switchgear unit, the entire ORU could have been damaged enough to stop functioning, which would have made power delivery impossible and would have led to a shutdown of the neighbouring reactor.
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The transformer fire atop the Kalinin NPP on June 23 2010.

According to residents of Udomlya, which is located five kilometres from the NPP, who were interviewed by Bellona Web, there was a transformer explosion on the same ORU in the winter three years ago. The explosion was even audible in the city. The current explosion caused turmoil in Udomlya. Smoke was visible over the top of the nuclear power plant, and some residents rushed to get photos and video that were published on the internet.

Accidents with transformers can have a serious impact on nuclear power plants. A transformer explosion at the Kola NPP, in Russia’s Northwestern Murmansk region last February, caused flying debris to damage other equipment at the station. According to information obtained by Bellona Web, the Kola NPP transformer explosion not only downed two power lines but cut off the cooling of water in the on-site spent nuclear fuel storage basins situated near reactors.

However, the Russian nuclear industry refuses to acknowledge such accidents as dangerous and suggests that they be assigned a zero-level on the seven-point International Nuclear Event Scale, which charts the impact of nuclear accidents and incidents. A zero is considered a “deviation” where a “3” is a “serious incident” and a “7” is a “major accident.” Russia therefore considers the exploding transformers to be insignificant to the safety of its nuclear plants and personnel.

Rosenergoatom’s press office said that on Sunday, July 25 at 10:15 am the No 1 reactor unit was put back online after a temporary shutdown.

In all, the shutdown resulting from the fire lasted 43 hours and the grid lost 43 kilowatt-hours of power. Whether the reactor has been safely relaunched will become clear in time. Incidents potentially leading to serious emergency situations have not been infrequent at Russia’s nuclear power plants of late: Recently, Kola NPP’s No. 3 reactor, after a short shutdown, only managed to stay online for nine hours before it was automatically shut down due to yet another mulfunction."

The head of the Federal Nuclear and Radiation Safety Authority of Russia Andrei Malyshev said at a press-conference being hold at Kalinin NPP that the operation license for Kalinin power unit 3 is under consideration. A license for the completion of its construction was issued earlier.

2003-07-16

Startup of the Kalinin Unit 4 is planned to be carried out according to the Russian Federation Government´s "Strategy of Nuclear Power Development in Russia in the first half of the 21st century" until 2010.